Medical Marijuana: The Myths and Realities

MARCH 18, 2015
Yvette C. Terrie, BSPharm, RPh
Marijuana has been used for medicinal purposes for more than 3000 years.
Marijuana, also known as cannabis, has been used for more than 3000 years for the treatment and management of pain, digestive issues, and psychological disorders.1 Despite the fact that marijuana is thought to be useful for treating several medical conditions and symptoms, there is great debate about its safety and efficacy.1 The FDA has not approved marijuana for any medical condition, yet a growing number of states are legalizing its use for the treatment and management of certain medical conditions.1

Currently, medical marijuana is legal in 23 states and the District of Columbia, and recreational use of the drug in small quantities is legal in Washington and Colorado.2-5 All the states that have legalized medical marijuana require a doctor’s approval, and all states but Washington require either an ID card that needs to be shown at the dispensary or enrollment in a patient registry.2-4 Many of the states that allow medical marijuana use have an online application process and require a patient fee.2,3 In addition to receiving an ID card, patients in most states are required to obtain a signed document from their physician indicating the condition being treated and that medical marijuana is the recommended treatment.3 Laws regarding the use of medical marijuana for treating specific conditions vary by state, and restrictions are in place regarding the amount of marijuana that can be dispensed at each visit.2,3

For What Conditions Is Medical Marijuana Used?
The most common reasons for medical marijuana use are relieving pain, controlling chemotherapyrelated nausea and vomiting, and stimulating appetite in patients with cancer and/or HIV/AIDS.4-10 Additionally, results from a 2014 study by the American Academy of Neurology reported that medical marijuana may be beneficial in easing some of the symptoms associated with multiple sclerosis.9

Glaucoma has been treated using medical marijuana since the 1970s, and studies show that medical marijuana decreases intraocular pressure (IOP) in patients with glaucoma.10 Additional research by the National Eye Institute concluded that although IOP is lowered following medical marijuana use, the pressure decrease is short-lived (typically 3 to 4 hours).10 This short period of relief is a major drawback, and many health care professionals prefer the traditional therapeutic approaches of prescription medication and surgical procedures because they have been proved to be effective for treating glaucoma.10 In June 2014, the American Academy of Ophthalmology stated that it does not recommend marijuana or other cannabis products for the treatment of glaucoma.10,11

Results from a clinical study published in the journal Neurology reported that medical marijuana may benefit individuals with chronic pain, nausea, and vomiting resulting from chemotherapy; lower IOP in those with glaucoma; and reduce spasm-related pain and painful burning and numbness associated with multiple sclerosis; however, more research is needed.3,8,12 Results from some studies have shown that medical marijuana may be beneficial in treating neuropathic pain.8

Scientists are exploring whether the active ingredients in marijuana may be beneficial and are investigating its use for treating neurologic conditions such as seizure disorders, multiple sclerosis, Crohn’s disease, and Parkinson’s disease, but more research is needed.6,8